Effect of different sources of phosphate on growth parameters, biomass production and nutrient content of green manure crops

Abstract

A field experiment was conducted at Mandouri Teaching Farm of Viswavidyalaya to study the effect of single superphosphate (SSP), partially acidulated rock phosphate (PARP) and rock phosphate (RP) on growth parameters, biomass production and nutrient content of green manure crops. At harvest, highest plant population (314.4 plants m-2) was observed in berseem (Trifolium alexandrinum), sunnhemp (Crotalaria juncea) recorded maximum height (86.00 cm) and also produced highest number of nodules plant-1 (45.41), while the nodule size of sesbania (Sesbania aculeata) was largest (2.52 mm). Green and dry matter yields of sunnhemp, cowpea (Vigna sinensis), ricebean (V. umbellata), sesbania and berseem were 21.42 and 4.39, 16.81 and 3.41, 15.42 and 3.21, 19.78 and 3.93 and 18.59 and 3.64 t ha-1 respectively. The differences in values of growth parameters and biomass production under SSP, PARP and RP treatments were non-significant. At harvest sesbania (Sesbania aculeata), sunnhemp (Crotalaria juncea) and cowpea (Vigna sinensis) contained maximum N (1.960%), P (0.341%) and K (2.054%) respectively. Sunnhemp was superior in N-fixation (134.01 kg ha-1) and application of SSP resulted in fixation of highest amount of nitrogen (110.01kg ha-1)